
The Prevalence of Metallo β-Lactamases
in the Clinical Isolates of Pseudomonas
aeruginosa in a Tertiary Care Hospital:
An Alarming Threat
1200-1202
Correspondence
Dr. Nutan Narayan Bhongle
140, Jaidurga Colony 1, Narendra Nagar (South),
Nagpur, India.
Phone: 9921024500
E-mail: Nutan.bobade@yahoo.co.in
Introduction:
Pseudomonas aeruginosa is most frequently responsible for nosocomial infection. Current isolates of P. aeruginosa are often multi-drug resistant.
Objective:
Thus present study was done to find out prevalence of metallo-β-lactamases (MBL) in clinical isolates of P. aeruginosa.
Methods:
A total 310 clinical isolates of Pseudomonas were identified and 200 clinical isolates were selected for the study based on their resistance to atleast - 2 third generation cephalosporins.
Results:
29(9.35%) isolates of P. aeruginosa were having zone size <28mm for imipenem , 27 were positive for MBL by EDTA double -disc synergy test (EDTA DDST) and all 29 were positive by modified Hodge test. Minimum inhibitory concentration (MIC’s) were determined by the agar dilution method and 26 isolates out of 29 were resistant, 2 were intermediate isolates & 1 was susceptible as per Clinical and Laboratory Standards Institute (CLSI ) breakpoints. Out of 29 MBL producing isolates, 25 were sensitive to both polymyxin B and colistin, 3 isolates were resistant to polymyxin B but sensitive to colistin, 1 was resistant to polymyxin B and colistin both by disc diffusion method. Sensitivity of MBL producing strains to polymyxin B was found to be 86% and that of colistin was 96.55% in our study.
Conclusion:
The early detection of MBL carrying organisms together with judicious use of antibiotics help in extending the longevity of carbapenems, the last resort antibiotic. MBLs are the major threats for the 21st century which pertain to bacterial drug resistance.